This invention relates to a fuel and lubricating oil supply device of the type, which has found a practical application to a rotary piston engine, and in which lubricating oil and fuel are both fed through an intake passage to a combustion chamber of the engine.
A fuel and lubricating oil supply device of the type of the prior art has been such that lubricating oil is injected through a metering pump into an intake passage on the upstream or downstream side of a throttle valve of a carburetor, and diffused into a mixture charge passing through the intake passage, thus being fed to a combustion chamber. In the meantime, as a countermeasure against exhaust gases and from the viewpoint of reduction of fuel consumption, there has recently arisen a demand for using a lean mixture charge. The use of a lean mixture charge however is accompanied by a problem of the failure in achieving smooth running of an engine. To solve the problem, it is desirable to provide a heating device in a bent portion of an intake passage connecting a fuel supply portion with a combustion chamber of the engine, which heating device consists of a heating plate which is so arranged as to be heated with such as exhaust gases, so that a mixture charge may be completely gasified, thus ensuring the smooth running of the engine.
However, with the fuel and lubricating oil supply device of the type in which fuel and lubricating oil are injected into the intake passage on the upstream of the heating device, lubricating oil and fuel are both subjected to heating. This impairs gasification of fuel as well as causes a change in quality due to heat, of lubricating oil, which leads to deterioration of lubricating oil. Furthermore, in the event of lubricating oil being stuck to the heating device in the carburetor, complete gasification of such lubricating oil is failed, with the resultant deposit of solid matters from the lubricating oil onto the heating plate. This enhances the premature failure in function of the heating plate.